EXECUTABLE UML AND MBSE

Transcription

1 EXECUTABLE UML AND MBSE What Executable UML does, how it is totally different from UML, and how it fits with other Executable languages Leon Starr MODEL INTEGRATION LLC 1 LiU Seminar xuml MBSE - November 16, 2017

2 FUNDAMENTAL IDEA OF MODELING A model isn t the thing you are modeling. To be useful, a model must omit certain aspects of the real world subject to focus on the details of interest. 2-2 LiU Seminar xuml MBSE - November 16, 2017

3 EXCLUDED DETAILS ARE STILL IMPORTANT Just because a detail is systematically ignored, doesn t mean that it is not important Layout diagram Schematic Focuses on layout geometry Is applied to schematic Focuses on component properties and connectivity Excludes layout details 3-3 LiU Seminar xuml MBSE - November 16, 2017

4 MODELING LANGUAGES, PURPOSES AND REQUIRED SKILLS What about UML? Simulink electronics/optronics control (usage at SAAB) physical systems structure 4-5 LiU Seminar xuml MBSE - November 16, 2017

5 UML PURPOSE AND SKILLS Requirements modeling High level code UML profiles Lower level code Just sequences Use cases Lot s of other uses Executable UML UML is not a modeling language. It is a standardized set of of object-oriented notations for many purposes. 5-4 LiU Seminar xuml MBSE - November 16, 2017

6 EXECUTABLE UML Modeling language Our purpose is to model requirements imposed by the real world: book white papers (shlaer-mellor method) Information Rules and constraints Real world behavior Essential computation and to separate these from the platform. Mathematical, executable semantics for each model type Doesn t presume object-oriented implementation 6-3 LiU Seminar xuml MBSE - November 16, 2017

7 AN EXAMPLE XUML MODEL 7 LiU Seminar xuml MBSE - November 16, 2017

8 AIR TRAFFIC CONTROL EXAMPLE Subject matter (domain) ATC Center OAK21C SFO37B SJC18C Gwen ATC67 Rating: B Login: T11:00 (On Duty) DS1 Loc: Front Cap: 20 DS3 (not in use) Toshiko ATC53 Rating: A Login: T15:00 (On Duty) DS2 Loc: Front Cap: 45 Ianto ATC51 Rating: C Last shift ended: T17:00 (Not logged in) Loc: Center Cap: 30 8 LiU Seminar xuml MBSE - November 16, 2017

9 RULES / REQUIREMENTS 1) A controller can not direct air traffic while off duty. 2) An on duty controller must be logged into a duty station. 3) A duty station may or may not be available. 4) A control zone must have its traffic directed by one air traffic controller at all times. 5) An air traffic controller may not work a shift longer than two hours and fifteen minutes. 9-6 LiU Seminar xuml MBSE - November 16, 2017

10 THE CLASS MODEL 0..* LiU Seminar xuml MBSE - November 16, 2017

11 POPULATION Air Traffic Controllers Same object ID {I} Name Rating ATC53 Toshiko A ATC67 ATC51 Gwen Ianto B C Superclass table ID {I, R1} ATC53 ATC67 On Duty Controllers Time logged in Duty Station {R2} 9/27/13 15:00 DS2 9/27/13 11:00 DS1 Subclass tables Off Duty Controllers ID {I, R1} Last shift ended ATC :00 Duty Station SJC18C SFO37B Air Traffic Controllers Number {I} Location Capacity DS1 Front 20 DS3 DS2 Center Front User {R3} 67 None 53 OAK21C ATC53 Time logged in 9/27/13 15:00 ATC67 Time logged in 9/27/13 11:00 On Duty Controllers ATC51 Off Duty Controllers Last shift ended :00 Control Zones Name Traffic Controller SJC18C CZ ATC53 SFO37B CZ ATC53 OAK21C CZ ATC67 11 LiU Seminar xuml MBSE - November 16, 2017

12 LOGIC AND CONSTRAINTS Off Duty ATC goes On Duty? 0..* LiU Seminar xuml MBSE - November 16, 2017

13 LOGIC AND CONSTRAINTS If there is only one On Duty Controller, can he or she go Off Duty? 0..* LiU Seminar xuml MBSE - November 16, 2017

14 LOGIC AND CONSTRAINTS If every Control Zone is being directed, can another Off Duty Controller log in? 0..* LiU Seminar xuml MBSE - November 16, 2017

15 LOGIC AND CONSTRAINTS Do we know when a shift should end? 0..* LiU Seminar xuml MBSE - November 16, 2017

16 LOGIC AND CONSTRAINTS Do we know when a shift should end? 0..* Shift Specification 0..1 Name {(} {I}:: Name Min break : Duration Max shift : Duration 12-6 LiU Seminar xuml MBSE - November 16, 2017

17 EXCLUDED DETAILS States, algorithms, functions are filtered out Platform specific features are filtered out Implementation choices are filtered out Lean modeling language minimal symbols So you can define and evaluate the application logic without distraction 13-5 LiU Seminar xuml MBSE - November 16, 2017

18 MODELING BEHAVIOR WITH STATES AND ACTIONS migrate to On Duty Controller my station.= Duty Station( Number: in.station ) link /R3/my station Time logged in = _now.hms Logged in -> me In use -> my station Actions State models Class Model 14 LiU Seminar xuml MBSE - November 16, 2017

19 OFF DUTY Ready for duty( Station ) Verifying Adequate Break the shift spec.= Shift Specification() // selects singleton if ( _now - Last shift ended < the shift spec.min break ) Log in( in.station ) -> me else Cannot go on duty -> me Logging Out User leaving -> /R3/Duty Station migrate to Off Duty Controller Last shift ended = _now.hms Off duty -> me Log out Log in( Station ) Logging In migrate to On Duty Controller my station.= Duty Station( Number: in.station ) & /R3/my station // link station Time logged in = _now.hms Logged in -> me In use -> my station Verifying Full Handoff Logged in Must hand off zones if /R1/On Duty Controller/R2/Control Zone{ Must handoff zones -> me UI.Control Zones Active( ATC: ID ) } else Log out -> me ON DUTY Ready for a break Handoff complete Handoff( Zone, Controller ) Handing off Control Zone hoff zone.= /R2/Control Zone( Name: in.zone ) if in.controller == ID UI.Cannot handoff to self( Controller: in.controller ) else { new controller.= On Duty Controller( ID: in.controller ) swap hoff zone/r2/on Duty Controller with new controller!new missing: UI.Unknown controller( Controller: in.controller)!old missing: UI.Zone not handled by( Controller: ID) } // swaps controllers and checks for errors Handoff complete -> me 15 LiU Seminar xuml MBSE - November 16, 2017

20 EXCLUDED DETAILS How execution is implemented How synchronization is implemented Distribution across processes/processors 16-4 LiU Seminar xuml MBSE - November 16, 2017

21 ACTIONS EXCLUDED DETAILS Logging In migrate to On Duty Controller my station.= Duty Station( Number: in.station ) & /R3/my station // link station Time logged in = _now.hms Logged in -> me In use -> my station Non-essential ordering of computation Data access implementation 17-3 LiU Seminar xuml MBSE - November 16, 2017

22 FOUNDATION SEMANTICS of the xuml language 18 LiU Seminar xuml MBSE - November 16, 2017

23 CLASS MODEL SEMANTICS A class is a set of things in the real world such that all things in the set: Aircraft Tail number {I} Altitude Speed Heading have the same characteristics exhibit the same behavior are constrained by the same rules Aircraft Tail Number {I} Altitude Airspeed Heading 19-6 LiU Seminar xuml MBSE - November 16, 2017

24 RELATIONAL THEORY SET THEORY FUNCTIONS y = f(x) PREDICATE LOGIC forall x such that 20 LiU Seminar xuml MBSE - November 16, 2017

25 A CLASS PREDICATE Each class in your model is an n-ary predicate where n is the number of attributes An ATC has an ID i, a Name n and a Rating r We can turn this into a proposition (true/false statement) by instantiating it ATC53 is named Ianto and has Rating B (true/false statement) If the instance does not exist, it is false 21-6 LiU Seminar xuml MBSE - November 16, 2017

26 STATE MODEL SEMANTICS Aircraft abstraction Tail number {I} Altitude Airspeed Heading Position Same characteristics, rules, behavior abstraction Common lifecycle 22-2 LiU Seminar xuml MBSE - November 16, 2017

27 THE THEORY Moore state machine Leslie Lamport Time, Clocks, and the Ordering of Events in a Distributed System Video animation of the platform independent synchronization rules Also described here 23-4 LiU Seminar xuml MBSE - November 16, 2017

28 PLATFORM INDEPENDENT EXECUTION RULES What happens when event occurs while instance is executing a state activity? Are events prioritized? What is the duration of an activity? Can event arrival order be guaranteed? 24 LiU Seminar xuml MBSE - November 16, 2017

29 ACTION SEMANTICS Access data from class model Based on relational semantics Send/receive event data on state model Follows state machine execution rules Perform computations Essential sequence only No data implementation assumptions 25 LiU Seminar xuml MBSE - November 16, 2017

30 THE THEORY Data access: Relational operations Sequencing: Data flow semantics Now (system variable) Data types: Type theory Off Duty Controller Write Time logged in me in.station id On Duty Controller Migrate On Duty Controller my station Select R1 me Link Duty Station me Logged in R3 In use Signal Signal 26 LiU Seminar xuml MBSE - November 16, 2017

31 DOMAINS 27 LiU Seminar xuml MBSE - November 16, 2017

32 DOMAIN DEFINITION A domain is a distinct subject matter with its own vocabulary, rules, constraints and behavior. Example: Linear Algebra Not a domain: Stuff that runs on processor X, Stuff in library Y, Stuff dept Z is coding up Domain partition of a system excludes details of deployment onto any particular platform features LiU Seminar xuml MBSE - November 16, 2017

33 EXAMPLE DOMAIN SEPARATION Elevator Management! Floor selection! Cabin dispatching! Door open/close timing Elevator uses Transport Bridge between domains! Safe acceleration! Precise transport Shaft Load Acceleration Profile Door Axis of Motion Bank Cabin Motor gotofloor (Cabin 3, Floor 6) cabinarrived () move (Load 14, Position , Ramp 3B) movecompleted () 29-3 LiU Seminar xuml MBSE - November 16, 2017

34 A COMPLETE DOMAIN CHART Elevator Management UI Transport Signal I/O xuml xtuml Model Execution Architecture Hand coded Existing C 30 LiU Seminar xuml MBSE - November 16, 2017

35 CODE GENERATION 31 LiU Seminar xuml MBSE - November 16, 2017

36 TRANSLATION PRINCIPLES Models are not modified by translation process Information is added, usually via some DSL (domain specific language / model markup) A runtime MX (model execution) platform is supplied A code generator which populates this platform (from the DSL) is provided The MX and code generator work for a class of platforms, e.g. Embedded microcontroller Cloud Fault tolerant distributed 32-9 LiU Seminar xuml MBSE - November 16, 2017

37 EXAMPLE APPROACH FOR A MICROCONTROLLER Pycca Translation Workflow Platform Independent Platform Specific Identify Domains Build & Document Models Specify Domain Mapping Populate Models Populate Mappings Create Pycca Script Write Bridge Code Code / Provide Non-Modeled Domains Use any model draw and text editing tools Spreadsheets Transform and Populate Text Editor Pass along Coded by hand Provided Platform Model Generate Model Code Non-Model Code ST/MX Runtime Provided Model Object Code Link System Executable Compile Non-Model Object Code 33 LiU Seminar xuml MBSE - November 16, 2017

38 SUMMARY Executable UML is a complete modeling language Concrete, unambiguous models of application requirements Executable, platform independent modeling Mathematical foundations Does not presume an OO implementation Domains accommodate other MBSE languages Model Translation Models are not modified to generate code So models can be reused and redeployed Models are stable while platform details change 34 LiU Seminar xuml MBSE - November 16, 2017

39 MORE RESOURCES BOOKS SITES modelstocode.com executableuml.org SOCIAL MODEL INTEGRATION LLC facebook.com/modelint twitter.com/leon_starr Leon Starr 35 LiU Seminar xuml MBSE - November 16, 2017